Retractable safety edge for doors



A ril 25, 1967 B. w; TUCKER, JR 3,315,766

RETRACTABLE SAFETY EDGE FOR DOORS Filed Nov. 12, 1965 2 Sheets-Sheet 1 FIG. 5

INVENTOR BENJAMIN WHITEHEAD TUCKER JR BY )7 i WTORNl-IY April 25, 1967 B. w. TUCKER; JR 15,

RETRACTABLE SAFETY EDGE FOR DOORS 2 Sheets-Shet 2 Filed Nov. 12, 1965 INVENTOR BENJAMIN WHITEHEAD, TUCKER UR.

BY #CKWATTORNEY United States Patent 3,315,766 RETRACTABLE SAFETY EDGE FOR DOORS Benjamin Whitehead Tucker, Jr., South Orange, N.J., as-

signor to Otis Elevator Company, New York, N.Y., a corporation of New Jersey Filed Nov. 12, 1965, Ser. No. 507,439 6 Claims. (Cl. 187-52) doors as commonly used in elevator cars and entranceways, and will be described in that connection.

Modern elevator systems are frequently operated without attendants and accordingly the doors are closed automatically as a prerequisite for starting the car. Since there is no attendant present to act as a guard, precautions are taken to minimize the possibility of passengers being struck by the closing doors as they enter or leave thecar. Various types of mechanisms have been used in the past to arrest the closing motion of the door when a person is in danger of being struck. One type of mechanism projects an electrostatic field in front of the leading edge of the door and is arranged so that disturbance of this field caused by the presence of a passenger acts to stop the door and preferably also to reopen it. Another type of mechanism projects one or more light beams across the opening, interruption of which causes the door to reopen. A third type comprises a retractable member, often called a safety edge, projecting beyond the leading edge of the door. Upon contact with a person, the edge retracts and actuates a control mechanism which reopens the door. The present invention is of the latter type.

A yieldable safety edge, to be effective, must project beyond the leading edge of the door proper so that upon yielding, the door may be brought to a stop before the door itself strikes the person. Such projection inherently widens the door and, unless retracted when not in use, effectively narrows the opening available for passenger transfer. For example, in the case of a single door, the door jamb at the leading edge when the door is fully closed must be positioned to overlap the door proper slightly and in addition must be wide enough to accommodate the safety edge. When the door is fully open, either the safety edge extends into the opening or the jamb must be positioned beyond the door proper, flush with the safety edge. But since the safety edge is required only during the closing operation, it may be retracted at other times without reducing the safety of operation.

It is apparent that it is desirable for a safety edge to be (1) retracted when the door is in its fully closed position; (2) retracted during the normal door opening operation; (3) retracted when the door is fully opened; and (4) extended and operative during the entire door closing operation.

Various arrangements for retracting safety edges have been proposed in the past, but none have been entirely satisfactory. Many have but partially solved the problem. Many have been quite complex. One problem causing such complexity is that yielding, or retracting, of the edge caused by contact with a person must arrest the closing movement of the door, yet when the edge is to be retracted as the door approaches its fully closed position, such retraction must not prevent the completion of the closing operation.

It is a general object of the present invention to provide an improved protective mechanism for doors.

3,315,766 Patented Apr. 25, 1967 It is another object to provide an improved protective mechanism including an extensible safety edge on the leading edge of the door which yields upon engagement with an obstruction thereby actuating a control switch.

Another object is to provide an imporved protective mechanism including a safety edge which is extended only during the door closing operation.

Another object is to provide an improved protective mechanism including a safety edge which is retracted when the door is fully closed, during the door opening operation, and while the door is fully open.

Briefly stated, a preferred embodiment of the invention comprises a safety edge mounted adjacent to the leading edge of the door, biased toward an extended position but movable sidewise toward a retracted position. A two position switch is fastened to the safety edge and is internally biased toward a first position at which door closing is prevented. A lever assembly formed with first and second arms is pivotally mounted on the safety edge for limited rotation in each direction and is spring biased in a first direction of rotation. When the safety edge is extended, a stop member or bumper fastened to the door engages the second arm of the lever assembly and holds the assembly against the urging of its spring to the limit of its second direction of rotation. In this position the first arm of the lever assembly engages the actuator of the switch, holding it in the second position at which door closing is permitted. When the edge is retracted, as by engagement with an obstruction, the first arm moves out of engagement with the bumper, allowing the spring to rotate the lever assembly in the first direction. As a consequence, the second arm releases the actuator, allowing the switch to be actuated to its first position (at which door closing is prevented).

A second stop member or bumper is fastened to the car in such position that, as the door approaches its closed position, the second bumper engages the lever assembly tending to rotate it in its second direction. But with the edge extended, the assembly is already at its limit of rotation so that further closing movement of the door retracts the safety edge without actuating the switch.

An electromagnet is provided to hold the safety edge retracted during door opening.

For a clearer understanding of the invention, reference may be made to the following detailed description and the accompanying drawing, in which:

FIGURE 1 is a partly schematic elevation view of the invention as applied to an elevator car door, taken with the rear door panel removed and with the door in its fully closed position;

FIGURE 2 is a cross section view taken on the line 22 of FIGURE 1;

FIGURE 3 is a view similar to FIGURE 1 showing the door fully open and the safety edge extended;

FIGURE 4 is a cross section view taken on the line 4-4 of FIGURE 3;

FIGURE 5 is a fragmentary elevation view showing the positions of the parts with the door partially open and the safety edge retracted; and

' FIGURE 6 is a fragmentary elevation view showing the positions of the parts with the door partially open and the safety edge actuated.

Referring first to FIGURE 1, there is shown an elevator car 11 on which a door 12 is mounted. The door 12 is formed with, or has fastened thereto, a bracket 13 which extends upwardly from the door and is offset therefrom in a direction toward the interior of the car, that is, into the paper as viewed in FIGURE 1. The bracket 13, on the remote side thereof, carries rollers by which the door is mounted for sidewise movement relative to the car.

Such rollers, and the tracks upon which they ride, are

of conventional construction and it has been deemed unnecessary to show or describe them in detail.

As shown in FIGURE 2, the door 12 is hollow and includes spaced apart front and rear panels 14 and 15 respectively. The front panel 14 is on that side of the door which is toward the interior of the car. The rear panel 15 is made in two parts, a main portion 16 and an edge portion 17 fastened thereto by bolts 18. In the closed position shown, the leading edge of the door 12 is positioned in an L-shaped recess in a door jamb 19. A safety edge, indicated generally by the reference charracter 21, is positioned between the panels 14 and 15 and comprises a metal frame member 22 of hollow rectangular cross section to which is fastened a U-shaped resilient nosing 23. The safety edge 21 is mounted on the edge portion 17, as will be more fully explained, so as to be movable from the retracted position shown in FIGURES 1 and 2 to an extended position as shown in FIGURE 3 at which it protrudes beyond the edges of the panel 14 and the edge portion 17 of the panel 15.

As shown in FIGURES l and 3, the safety edge 21 has fastened thereto a pair of laterally extending brackets 25 and 26 which are pivotally fastened by pins 27 and 28 to two generally triangular plates 31 and 32 respectively. As best shown in FIGURE 4, the plate 31 is pivotally mounted by a pin 33 to the edge portion 17 of the rear panel 15. The plate 31 is also pivotally connected by a pin 34 to an elongated tie member 35 which is disposed vertically and substantially parallel to the safety edge 21. The tie member 35 is also pivotally connected to the plate 32 by a pin 36. The plate 32 is pivotally mounted to the edge portion 17 by a pin 37.

The elements 31 and 32, although made in the form of generally triangular metal plates, act as and are in effect bell crank levers. The element or plate 31, for example, has, in effect, a first arm interconnecting the pins 33 and 34 and a second arm interconnecting the pins 33 and 27. The plate 32 likewise is a bell crank lever having first and second arms connecting the pin 37 with the pins '36 and 28 respectively. It is apparent that up and down motion of the tie member 35 causes lateral back and forth motion of the safety edge 21, and vice versa. A tension spring 41 is connected between a bracket 42 fastened to the tie member 35 and a bracket 43 fastened to the edge portion 17 so as to urge the member 35 down and thesafety edge 21 to its extended position shown in FIGURE 3. A hydraulic cushioning mechanism 44 cushions the safety edge 21 'as' it moves toward its extended position.

A lever assembly 51 is pivotally mounted by a pin 52 to a bracket 53 rigidly fastened to the safety edge 21. The assembly 51 includes a first upstanding arm 54 adapted to engage, at times, a bumper 55 fastened to the bracket 13 of the door 12. The bumper 55 is preferably a resilient roller rotatably mounted. The lever assembly 51 also includes a second arm 56 comprising a rigid depending strap 57 to which is fastened a bolt 58 which engages an actuator 61 of a switch 62. A resilient roller 63 is rotatably mounted on the lever assembly 51, in the upper right portion as viewed in the drawing, above the pivot pin 52. This roller 63 at times engages a bumper 64 mounted by a bracket 65 on the car 11. A compression spring 66 acts between the safety edge 21 and the lever assembly 51 at a point below the pivot pin 52 so as to urge the assembly 51 to rotate in a first or clockwise direction, as viewed in the drawing. Rotation in this direction is limted by varous mechanisms under different circumstances, as will be more fully explained. In FIGURE 1, rotation is limited by the engagement of the roller 63 with the bumper 64; in FIG- URE 3, rotation is limited by engagement of the arm 54 with the bumper 55. A bolt 67 fastened to the safety edge 21 engages the actuator 61 just opposite the bolt 58 and "serves both to protect the switch 62 by limiting the movement of the actuator 61 and, in conjunction 4 with the actuator 61, bolt 58 and strap 57, to limit the rotation of the lever assembly 51 in the second or counterclockwise direction.

The previously mentioned switch 62 is rigidly fastened to the safety edge 21, a shown, and is internally biased toward a first condition at which, as illustrated in FIG- URE 5, the actuator 61 extends to the left as viewed in the drawing. It is contemplated that the switch 62 will be connected in the door control circuit in such a way that when it is in its first condition, door closing is prevented, while when in its second condition, as illustrated in FIGURES l and 3, door closing is permitted.

An electromagnet 71 having two pole pieces 72 and 73 is mounted on the edge portion 17. An armature 74, mounted on the safety edge 21, cooperates with the magnet 71.

Summarizing the above description, it is apparent that the safety edge 21 and all of its associated elements, except the bumpers 55 and 64, are mounted, either directly or indirectly, on the edge portion 17 of the panel 15. The spring bracket 43, the cushioning mechanism 44 and the electromagnet 71 are mounted directly on the edge portion 17. The pins 33 and 37, fastened to the edge portion 17, support the remaining items. Bell crank levers 31 and 32, supported by the pins 33 and 37, in turn support the tie member 35 and the safety edge 21. The latter supports the armature 74, the switch 62, the bolt 67 and the lever assembly 51. The latter thus moves back and forth with the safety edge 21 and is also rotatable with respect thereto. All of these parts may be assembled and mounted on the edge portion 17 be= fore it is bolted to the main portion 16.

Let us consider a full cycle of operation. In FIG= URE l the door is shown fully closed, adjacent to the door jamb 19. The roller 63 bears against the bum er 64, holding the lever assembly 51 at the limit of its rotation in the second direction, with the second arm 56 holding the actuator 61 in its second position against the bolt 67. The armature 74 engages the pole pieces 72 and 73 of the electromagnet 71.

Sometime before the door is to be opened, the elec= tromagnet 71 is energized. When the door is opened, it moves to the left, as viewed in the drawing. The elec= tromagnet 71 holds the edge 21 in its retracted position. The spring 66 continues to urge the assembly 51 to to tate in its first (clockwise) direction and as the door 12 starts to move, the assembly 51 rotates, holding the roller 63 against the bumper 64 until the assembly has been rotated sufi'iciently to cause a stop member 76 to engage the safety edge 21, thereby limiting the rotation in this direction. At the same time, the arm 56 swings to the left, allowing the switch 62 to assume its first condition. The edge 21 remains retracted, the assembly 51 remains rotated to its limit in its first direction, and the switch 62 remains in its first condition as the door continues its opening movement, finally reaching the fully opened position as shown in FIGURE 5.

The first step in the door closing operation is the deenergization of the electromagnet 72, which alows the spring 41 (FIGURES 1 and 2) to extend the safety edge 21. As the edge extends, the arm 54 is drawn to the right and engages the bumper 55 whereupon the lever assembly 51 is rotated in its second or counterclockwise direction to the position shown in FIGURE 3. Such rotation actuates the switch 62 from its first condition, shown in FIGURE 5, to its second condition, as shown in FIGURE 3. The door now moves to the right with the safety edge 21 in its extended, operative,- position.

Let it be assumed that an obstruction such as a passenger is encountered by the resilient nosing 23 of the safety edge 21 as the door moves toward its closed position. The safety edge 21 yields readily and starts to ret raot into the door. It need retract but a short distance, as shown in FIGURE 6, before the spring 66 rotates the lever assembly 51 and its arm 66 sufliciently to allow the switch 62 to be actuated to its first condition. As previously mentioned, theswitch 62 is preferably connected as part of a control circuit which, as soon as the switch 62 is actuated to its first condition, controls the door operator so as to stop the door and, preferably, to reopen it, at least partially, before attempting another closure. Such a control circuit may be of a conventional construction and has not been illustrated because its details are not a part of the present invention.

When the door moves away from the obstruction, the edge 21 is again extended by the spring41. As the edge extends, the arm 54 engages the bumper 55, rotating the lever assembly 51 in its second direction thereby actuating the switch 62 to its second condition at which door closing is permitted. The door may now again move toward its closed position. If there is now no obstruction, the door continues its movement toward the right with the safety edge remaining extended until it is within the recess in the door jamb 19 at which position the roller 63 engages the bumper 64 thereby stopping the forward movement of the safety edge 21. Continued movement of the door 12,- While the edge 21 remains stationary, has the effect of retracting the edge 21 with respect to the door. It is to be noted that although this continued movement of the door cause-s the bumper 55 to become disengaged from the arm 54, the lever assembly is held at its limit of rotation in its second direction and the arm 56 holds the switch 62 in its second condition. The door comes to rest in its fully closed position as illustrated in FIGURE 1.

From the foregoing it is apparent that applicant has provided an improved safety edge which is retracted out of the way except when it is needed during the door closing operation. Although a specific embodiment has been described in considerable detail for illustrative purposes, many modifications can be made within the spirit of the invention. It is therefore desired that the protection afforded by Letters Patent be limited only by its true scope of the appended claims.

What is claimed is:

1. Protective apparatus, comprising:

a structure,

a door mounted on said structure for sidewise movement relative thereto between an open and a closed position,

a bumper fastened to said door,

a safety edge mounted adjacent to the leading edge of said door and biased toward an extended position but movable sidewise to a retracted position,

a switch operable to first and second conditions rigidly fastened to said safety edge and including an actuator biased to urge said switch toward said first condition,

a lever assembly pivotally mounted on said safety edge for rotation relative thereto in first and second directions, and

spring means urging said lever assembly to rotate in said first direction,

said lever assembly including a first arm engaging said actuator for operating said switch to said second condition when said assembly is rotated in said second direction,

said lever assembly further including a second arm, positioned to engage said bumper as said safety edge moves from its retracted to its extended position, for rotating said asembly in said second direction.

2. Apparatus according to claim 1 in which:

said safety edge is biased by resilient means urging said safety edge toward said extended position, and

there is further provided a second bumper fastened to said structure and positioned to engage said lever assembly as said door approaches said closed position for retracting said safety edge while preventing said lever assembly from rotating in said first direction.

3-. Apparatus according to claim 2 further compris ing:

an electromagnet mounted on said door, and

an armature mounted on said safety edge and positioned to engage said electromagnet when said safety edge is retracted.

4. Apparatus according to claim 1 in which:

said structure is formed with an opening,

said door is hollow and includes spaced apart front and rear panels,

said open and closed positions of said door respectively expose and cover said opening,

said safety edge is mounted in the space between said panels adjacent to the leading edge of said door as said door closes,

said safety edge is principally within said space between panels when retracted, and in which said safety edge protrudes well beyond said leading edge of said door when extended.

5. Apparatus according to claim 1 further comprisfirst and second bell crank levers pivotally mounted on said door and each including first and second arms, and

an elongated tie member pivotally connected to said first arms of each of said bell crank levers,

said safety edge being pivotally connected to said second arms of each of said bell crank levers,

said bel-l crank levers being located on said door to position said safety edge adjacent to the leading edge of said door and movable relative thereto,

said safety edge being biased toward its extended position by spring means acting between said tie member and said door.

6. Protective apparatus, comprising:

an elevator car formed with an opening,

a hollow door, including spaced apart front and rear panels, mounted on said car for sidewise horizontal movement between an open and a closed position for exposing and covering said opening,

first and second bell crank levers pivotally mounted on said rear panel of said door in the space between panels and each including first and second arms,

a vertically disposed elongated tie member pivotally connected to said first arms of each of said bell crank levers,

a safety edge, including a resilient nosing, pivotally connected to said second arms of each of said bell crank levers,

said bell crank levers being located on said door to position said safety edge adjacent to the leading edge of said door as said door closes and being oriented so that said safety edge moves with said levers between a retnacted position, at which said safety edge is substantially flush with said leading edge of said door, and an extended position, at which said safety edge protrudes beyond said leading edge of said door,

a first spring acting between said door and said tie member for urging said safety edge toward said extended position,

a switch, operable to first and second conditions, rigidly fastened to said safety edge and including an actuator biased to urge said switch toward said first condition,

a lever assembly pivotally mounted on said safety edge for rotation relative thereto in first and second directions about a horizontal axis normal to said door panels,

stop means limiting the rotation of said lever assembly in each direction,

a second spring acting between said safety edge and said lever assembly for urging said assembly to rotate in said first direction,

said lever assembly including a first arm engaging said 7 8 actuator for operating said switch to said second an electromaguet mounted on said door, and condition as said assembly is rotated in said secan armature mounted on said safety edge and posiond direction, tioned to engage said electromagnet when said safety a first bumper fastened to said door, edge is retracted.

said lever assembly including a second arm,- positioned 5 to engage said first bumper as said safety edge moves References Clted by the Exammer from said retracted to said extended position, for UNITED STATES PATENTS rotating said assembly in said S co d dire ti n, 7 3,050,155 8/1962 Karmel 187-52 a second bumper fastened to said car and positioned 3,168,165 2/1965 Bagnasco 18752 to engage said lever assembly as said door ap- 10 3,194,345 7/1965 Kozak 187-51 preaches said closed position for retracting said safety edge While preventing rotation of said lever as- EVON BLUNK P 1 1mm y Examiner sembly in said first direction, H. C. HORNSBY, Assistant Examiner. 

1. POTECTIVE APPARATUS, COMPRISING: A STRUCTURE, A DOOR MOUNTED ON SAID STRUCTURE FOR SIDEWISE MOVEMENT RELATIVE THERETO BETWEEN AN OPEN AND A CLOSED POSITION, A BUMPER FASTENED TO SAID DOOR, A SAFETY EDGE MOUNTED ADJACENT TO THE LEADING EDGE OF SAID DOOR AND BIASED TOWARD AN EXTENDED POSITION BUT MOVABLE SIDEWISE TO A RETRACTED POSITION, A SWITCH OPERABLE TO FIRST AND SECOND CONDITIONS RIGIDLY FASTENED TO SAID SAFETY EDGE AND INCLUDING AN ACTUATOR BIASED TO URGE SAID SWITCH TOWARD SAID FIRST CONDITION, A LEVER ASSEMBLY PIVOTALLY MOUNTED ON SAID SAFETY EDGE FOR ROTATION RELATIVE THERETO IN FIRST AND SECOND DIRECTIONS, AND SPRING MEANS URGING SAID LEVER ASSEMBLY TO ROTATE IN SAID FIRST DIRECTION, SAID LEVER ASSEMBLY INCLUDING A FIRST ARM ENGAGING SAID ACTUATOR FOR OPERATING SAID SWITCH TO SAID SECOND CONDITION WHEN SAID ASSEMBLY IS ROTATED IN SAID SECOND DIRECTION, SAID LEVER ASSEMBLY FURTHER INCLUDING A SECOND ARM, POSITIONED TO ENGAGE SAID BUMPER AS SAID SAFETY EDGE MOVES FROM ITS RETRACTED TO ITS EXTENDED POSITION, FOR ROTATING SAID ASSEMBLY IN SAID SECOND DIRECTION. 